Driver/control circuit for a electro-luminescent element

Abstract

A driver/control circuit for a super thin lighting element display includes a DC power supply, a function interface, an inverter, and a component interface. The function interface is implemented by selectable inputs and control outputs of an integrated circuit, while the inverter is made up of the square wave output of the integrated circuit and a transformer isolated from the square wave output by a transistor, the primary winding of the transformer being connected between the power supply and the transistor, with the control electrode of the transistor being connected to the square wave output of the integrated circuit. Preferably, in the case of multiple lighting element control, the component interface includes transistors having control electrodes connected to the control outputs of the integrated circuit, while in the case of multiple lighting elements of different types, the inverter preferably includes either a plurality of transformers or a transformer having a plurality of different secondary windings, or a combination of different transformer and secondary winding arrangements.

We claim: 
     
       1. A control/driver circuit for a plurality of electro-luminescent lighting elements, comprising: a direct current (DC) power source; and   an integrated circuit, said integrated circuit including: a function interface including an oscillator, said function interface being arranged to output pulses through first output terminals of said integrated circuit to respective said electro-luminescent lighting elements, the timing and duration of said pulses determining on/off cycles of said electro-luminescent lighting elements; and   a component interface including means for converting pulses output by the oscillator into an approximate sine wave having a frequency and amplitude sufficient to cause a first one of said electro-luminescent lighting elements to emit light of a predetermined brightness and color when said lighting elements are activated by said pulses output from said function interface,     wherein said component interface includes at least two second output terminals of said integrated circuit for converting said pulses output by said oscillator into different approximate sine waves, each of said second output terminals being connected to an additional one of said electro-luminescent elements, at least one of said additional ones of said electro-luminescent lighting elements having different physical properties from said first one of said electro-luminescent lighting elements,   wherein said integrated circuit has a trigger input for initiating generation of said pulses, and control inputs for varying the timing and duration of said pulses to cause said outputs to activate a plurality of electro-luminescent lighting elements according to a predetermined pattern.   
     
     
       2. A circuit as claimed in claim 1, wherein said component interface includes a transformer having two secondary windings, said secondary windings having different numbers of turns. 
     
     
       3. A circuit as claimed in claim 1, wherein said component interface includes two transformers, the secondary windings of the two transformers having different numbers of turns. 
     
     
       4. A circuit as claimed in claim 1, wherein said component interface comprises a transformer, and wherein a primary winding of the transformer is connected between said DC power source and switching means for controlling the supply of voltage to said primary winding, said switching means in turn being opened and closed by a square wave output of said oscillator. 
     
     
       5. A circuit as claimed in claim 4, wherein said switching means comprises a first transistor having a base electrode connected to the output of the oscillator and a collector or emitter connected to said primary winding. 
     
     
       6. A circuit as claimed in claim 5, wherein said electro-luminescent lighting elements are connected between said component interface and control outputs of the integrated circuit, said control outputs controlling which of said electro-luminescent lighting elements is switched on according to inputs supplied to said control inputs. 
     
     
       7. A circuit as claimed in claim 6, further comprising a plurality of second transistors each having a control electrode connected to said control outputs of the integrated circuit, a collector and emitter of each of said second transistors being connected between a reference potential and a terminal of one of said electro-luminescent lighting elements, a second terminal of each of said electro-luminescent lighting elements being connected to a secondary winding of the transformer. 
     
     
       8. A circuit as claimed in claim 1, wherein said pattern is selected form the group consisting of flashing, random activation, sequential activation, chasing effects, fade in/fade out effects, scanning, and steady activation. 
     
     
       9. A circuit as claimed in claim 1, wherein an activation pattern for a first type of said electro-luminescent lighting elements is different than an activation pattern for a second type of said electro-luminescent lighting elements. 
     
     
       10. A circuit as claimed in claim 9, wherein said different types of electro-luminescent element have different shapes and colors. 
     
     
       11. A control/driver circuit for a plurality of electro-luminescent lighting elements, comprising: a direct current (DC) power source; and   an integrated circuit, said integrated circuit including: a function interface including an oscillator, said function interface being arranged to output pulses through first output terminals of said integrated circuit to respective said electro-luminescent lighting elements, the timing and duration of said pulses determining on/off cycles of said lighting elements, said pulses causing said output to activate said electro-luminescent elements according to a predetermined pattern selected from the group consisting of flashing, random activation, sequential activation, chasing effects, fade in/fade out effects, scanning and steady activation; and   a component interface including means for converting pulses output by the oscillator into an approximate sine wave having a frequency and amplitude sufficient to cause a first one of said electro-luminescent lighting elements to emit light of a predetermined brightness and color when said lighting elements are activated by said pulses output from said function interface,   wherein said component interface comprises a transformer, and wherein a primary winding of the transformer is connected between said DC power source and switching means for controlling the supply of voltage to said primary winding, said switching means in turn being connected to a second output terminal of said integrated circuit and opened and closed by said pulses output by said oscillator.     
     
     
       12. A circuit as claimed in claim 11, wherein said switching means comprises a first transistor having a base electrode connected to the output of the oscillator and a collector or emitter connected to said primary winding. 
     
     
       13. A circuit as claimed in claim 12, wherein said integrated circuit has a trigger input for initiating generation of said pulses, and control inputs for varying a timing and duration of said pulses to cause said outputs to activate a plurality of electro-luminescent lighting elements according to said predetermined pattern. 
     
     
       14. A circuit as claimed in claim 13, wherein said electro-luminescent elements are connected between said component interface and control outputs of the integrated circuit, said control outputs controlling which of said electro-luminescent elements is switched on according to inputs supplied to said control inputs. 
     
     
       15. A circuit as claimed in claim 14, further comprising a plurality of second transistors each having a control electrode connected to said control outputs of the integrated circuit, a collector and emitter of each of said second transistors being connected between a reference potential and a terminal of an electro-luminescent element, a second terminal of each electro-luminescent element being connected to a secondary winding of the transformer. 
     
     
       16. A circuit as claimed in claim 13, wherein an activation pattern for a first type of said electro-luminescent elements is different than an activation pattern for a second type of said electro-luminescent elements. 
     
     
       17. A circuit as claimed in claim 16, wherein said different types of electro-luminescent element have different shapes and colors. 
     
     
       18. A driver/control circuit for a electro-luminescent element display, where an inverter is implemented using a square wave oscillator of a simple integrated circuit and a transformer, and in which a primary winding of the transformer is isolated from the square wave output of the integrated circuit. 
     
     
       19. A circuit as claimed in claim 18, wherein said inverter comprises two transformers having secondaries with different numbers of turns. 
     
     
       20. A circuit as claimed in claim 18, wherein said transformer has two secondary windings having different numbers of turns. 
     
     
       21. A circuit as claimed in claim 18, wherein said integrated circuit is made up of at least two discrete chips in order to increase the number of control terminals.